Liquid $Q$ has a density that is twice that of liquid $R$. In liquid $R$, the pressure from the liquid at depth $x$ is $4\,\text{kPa}$. At what depth in liquid $Q$ will the pressure from the liquid be $7\,\text{kPa}$?
- A$\frac{2x}{7}$
- B$\frac{7x}{8}$
- C$\frac{8x}{7}$
- D$\frac{7x}{2}$